240
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter BGP view.
bgp
as-number
N/A
3.
Configure a confederation ID.
confederation id
as-number
By default, no confederation ID is
configured.
4.
Specify peering sub-ASs in the
confederation.
confederation peer-as
as-number-list
By default, no peering sub-AS is
specified.
Configuring confederation compatibility
If any routers in the confederation do not comply with RFC 3065, enable confederation compatibility to
allow the router to work with those routers.
To configure confederation compatibility:
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter BGP view.
bgp
as-number
N/A
3.
Enable confederation
compatibility.
confederation nonstandard
By default, confederation
compatibility is disabled.
Configuring BGP GR
GR ensures forwarding continuous when a routing protocol restarts or an active/standby switchover
occurs. Two routers are required to complete a GR process. The following are router roles in a GR
process:
•
GR restarter
—Performs GR upon a BGP restart or active/standby switchover.
•
GR helper
—Helps the GR restarter to complete the GR process.
A device can act as a GR restarter and GR helper at the same time.
BGP GR works as follows:
1.
The BGP GR restarter and helper exchange Open messages for GR capability negotiation. If both
parties have the GR capability, they establish a GR-capable session. The GR restarter sends the GR
timer set by the
graceful-restart timer restart
command to the GR helper in an Open message.
2.
When an active/standby switchover occurs or BGP restarts, the GR restarter does not remove
existing BGP routes, and it still uses these routes for packet forwarding. The GR helper marks all
routes learned from the GR restarter as stale instead of deleting them, and it still uses these routes
for packet forwarding. During the GR process, packet forwarding is not interrupted.
3.
After the active/standby switchover or BGP restart completes, the GR restarter reestablishes a BGP
session with the GR helper. If the BGP session fails to be established within the GR timer advertised
by the GR restarter, the GR helper removes the stale routes.
4.
If the BGP session is established, routing information is exchanged for the GR restarter to retrieve
route entries and for the GR helper to recover stale routes. You can use the
graceful-restart timer
wait-for-rib
command to configure the time for the local router to wait for the End-Of-RIB (End of
Routing-Information-Base) marker, and control the route convergence speed. If routing information